1. Field of the Invention
This invention relates to key-controlled switch lock assemblies and more particularly to electric, key-controlled switch lock assemblies for use with printed circuit boards.
2. Description of the Prior Art
Although much effect has been expended in developing various key-controlled switch lock systems for burglar alarms, automobile ignition and warning systems, and the like, all of these systems suffer from being complex, multipart systems which are expensive to manufacture and assemble. Instead of advancing towards qualities of simiplicity of operation, ease of manufacture and rapid assembly, prior art key-controlled switch lock devices have become increasingly complex in their construction, assembly and operation.
Furthermore, in the particular field of printed circuit board based equipment, such as computers, machine controllers, and other programmable electronic equipment, very little effort has been expended in constructing a key actuated switch lock for direct use with printed circuit boards in order to provide controlled access thereto. Presently, the only key actuated switch lock mechanisms employed in programmable electronic equipment and other printed circuit board based computers and controllers are conventional key lock switches. The key lock switches are expensive to manufacture and extremely costly to install for use with such equipment.
The only prior art patent directed to a key switch device for use with printed circuit boards, of which the present inventor is aware, is Sasuki U.S. Pat. No. 4,185,179. However, the Sasuki key switch device is totally inapplicable to the present invention, since that key switch device does not employ and does not teach a tumbler actuated switch lock which is rotated by the axial rotational movement of an actuating key between an OPEN and CLOSED position. Instead, the key-switch device of Sasuki employs a key which is moved laterally about an axis perpendicular to the central axis of the key, causing contacts to move laterally between a plurality of alternate positions, making contact between various modes of operation. In addition, the key-switch device of Sasuki suffers from the typical prior art drawbacks of requiring a plurality of components which are difficult to manufacture and assemble.
It is the principal object of the present invention to provide an electric, key-controlled switch lock which is easily and inexpensively manufactured and employable for initiating and terminating the flow of electric current through a printed circuit board.
Another object of the present invention is to provide an electric, key-controlled switch lock having the characteristic features defined above which can be directly mounted to a printed circuit board, easily and inexpensively.
Another object of the present invention is to provide an electric, key-controlled switch lock having the characteristic features defined above which is capable of providing restricted use of the electrical system to which it is operatively connected.
Another object of the present invention is to provide an electric, key-controlled switch lock having the characteristic features defined above which is manufactured from a minimum number of components all of which are quickly and easily assembled into the final product.
Other and more specific objects will in part be obvious and will in part appear hereinafter.